Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Predicate calculus with equality: Tarski's system S2 (1 rule, 6 schemes)
Axiom scheme ax-4 (Quantified Implication)
ala1
Next ⟩
al2im
Metamath Proof Explorer
Ascii
Structured
Theorem
ala1
Description:
Add an antecedent in a universally quantified formula.
(Contributed by
BJ
, 6-Oct-2018)
Ref
Expression
Assertion
ala1
⊢
( ∀
𝑥
𝜑
→ ∀
𝑥
(
𝜓
→
𝜑
) )
Proof
Step
Hyp
Ref
Expression
1
ax-1
⊢
(
𝜑
→ (
𝜓
→
𝜑
) )
2
1
alimi
⊢
( ∀
𝑥
𝜑
→ ∀
𝑥
(
𝜓
→
𝜑
) )